Patent Document 1 discloses a multiple polyphase winding motor which has a plurality of groups of polyphase winding groups in one alternating current (AC) motor, the polyphase winding groups each being composed of a polyphase winding and an inverter that drives the polyphase winding. In such a motor, each other's inverters are energized so that a torque ripple generated by one polyphase winding and a torque ripple generated in the other polyphase winding become reversed phases; and thus, the whole motor torque ripple can be cancelled out.